Similar Strombolian eruptions continued from April through June , with the plume rising m above the crater VSI, b. Incandescent volcanic materials were ejected to heights of m above crater rim.
Between 1 April and 17 May , earthquakes occurred each day. During June there were unofficial reports of unusually loud noises heard on the W coast of Java.
On 27 June, GMU scientists visited islands around Anak Krakatau and heard some very loud sounds; only some of which correlated to visual activity at Anak Krakatau. The observers compared their observations to a visit, when the volcano emitted steam-bearing discharges accompanied by lightning. The eruptions on 27 June appeared dissimilar because they were ash-rich and without visible steam. In addition, the 27 June eruptions produced string-shaped columns with mushroom-shaped tops; lightning was absent.
The group deployed two seismometers for five hours of observation. A vertical-component long-period seismometer 0. Typical seismograms, showing two of the three components recorded on Sertung Island, appear on figure Other events also showed the same 8-second delay between the seismic signal and these air waves.
The case shown was correlated with a small eruption that generated a loud sound and ultimately spawned an ash cloud of undisclosed dimension. Assuming a shallow source for the eruption, the travel times for first arrivals of the strong impulsive signals across the 3. Thus, the strong impulsive signals were probably due to pressure waves transmitted through the air. Information Contacts: Wahyudi and A. Brodscholl , GMU. During an approved visit on 6 November, the volcano was steaming but not erupting.
A smaller sulfur-stained plug was farther S in another depression. The landing site on the SE shore was a black-sand beach with tiny dunes of white pumice.
While climbing the SE slope of the older cone, the party crossed water-eroded fields of pyroclastic material dotted with volcanic bombs. The ascent to the summit went through deep cinder deposits covered with a blanket of loose breadloaf-sized stones. From the summit complicated internal crater structures could be seen.
The largest and most active fumaroles were inside this cone's S rim. A smaller cone within the larger one was almost horseshoe-shaped and steeper to the S. Bombs on the summit cone were as large as m in diameter. At about on 29 September, a Qantas Airlines pilot reported a thick plume near Krakatau that rose to an altitude of 3, m and drifted NW at low levels and E at high levels. There was no definite signature on GMS satellite images.
Although a pilot report described a 3. Lava flows during July-August reached the island's W coast and added to its size. Two vents emitted lava and Strombolian eruptions in the N part of the main crater. During October, ash explosions occurred every minute, followed by rumbling sounds and lava fountains as high as m above the crater.
The main crater produced all the activity during October with the other two craters remaining quiet. There were no lava flows released to the surface during October. However, weak red glow was occasionally observed at night from the Pasuaran observatory. Information Contacts: Wimpy S. Lyvers noted that the Indonesian government's 5-km exclusion zone around the island has not deterred local boat operators from anchoring offshore or even landing tourists on Anak Krakatau.
This cloud, however, was not seen in GMS satellite imagery. Members of the SVE visited the island twice in April. They learned that during March at Carita, a beach resort on the W coast of Java 40 km from the volcano, there were ashfalls and explosions from the volcano were heard. During April, emissions became less prominent and more irregular. During their first visit on April they did not observe any plumes. After landing they ascended to the first crest line where the group encountered several bread-crust bombs and their substantial impact craters.
As they were ascending the cone of the volcano the visitors felt the heated ground through their hiking boots. There were fumaroles on both the flank and the summit. The crater, m in diameter, was breached to the W; the crater floor was occupied by large blocks, and it was possible to distinguish two vents aligned on a fissure trending SE-NW. The group returned on April, after another eruptive episode. This time they observed enormous new blocks at the summit.
The S vent continuously emitted white steam; the N vent sporadically discharged brown-black ash that rose up to m above the vent. One projectile landed very close to the observation point.
The next morning, ash on the tents suggested that the volcano had another explosion. The group witnessed another eruption as they were leaving the island by boat at Cyr a French tourist-guide saw plumes accompanied by projectiles. He described the ash as an unusual pink color. During the night, incandescent explosions were took place about every 30 minutes; several incandescent blocks fell over the dome's N side.
The next morning, during a boat tour around the island, some blue smoke rose from mid-way up the W-SW flanks of the dome, conceivably a sign of minor lava flows. During the afternoon and evening of 17 May, Mike Lyvers visited the island by boat.
The previous few days, when observed from Carita Beach, the volcano had been quiet. In contrast, on 17 May it erupted almost continuously, issuing minor amounts of ash and sometimes a few bombs.
Occasionally, larger explosions sent incandescent ash high into the sky, generating a spectacular display of volcanic lightning and covering the cone with glowing bombs.
The volcano seemed to show no obvious pattern to its activity, with random fluctuations in the intensity of eruption.
Activity decreased early during the week of March. Weak booming noises were heard twice on 9 and 10 March, but plumes were not observed. At the end of the week booming noises were rare, and a white-gray ash plume was seen on 14 March that rose m above the summit. The current activity is a continuation of eruptions that began in This report combines their observations.
Seismic activity preceding and coincident with the eruption went undetected because of ballistic bomb damage to seismometers. Until 3 April, activity typically involved explosions per day. Beginning at about on 3 April ash explosions became almost continuous figures 12 and During the interval on 4 April, the volcano erupted every minutes from a new crater a few hundreds of meters S of the summit crater that formed during Accidental blocks, lava bombs, and ash reached heights of m above the crater rim.
About a third of the eruptions were Strombolian, with showers of lava and bombs occasionally 1 m across ejected m above the vent and falling onto the upper flanks. Some ballistic fragments cm in diameter rose above the associated ash cloud and landed m from the vent on the upper flanks before rolling down to the shore. Eruptions were often accompanied by thunderous blasts and rumbling sounds heard several kilometers from the crater, including at Pasauran and Kalianda observatories 42 km from Krakatau.
A wedge-shaped deposit of fresh ash and bombs was visible on the crater rim the rim is higher on the SE due to prevailing northwesterly winds that blow ash and other ejecta in that direction. Ash clouds were light gray.
The ash was crystal-poor and frothy, suggesting that it was mostly juvenile material. Nearly a dozen other solfataras discharged steam and non-condensible gas and deposited bright yellow native sulfur around vents near the summit figure Another fumarolic area was centered at m elevation on the W flank below the active crater. Scientists observed several boatloads of tourists who had landed on the accessible SE beach.
Officials had closed an area of 3 km radius around the vent, but many tourists defied the prohibition and climbed to the ridge m from the summit vents. Escaping gases continued to pose a very serious hazard. Caldera collapse, perhaps in AD, destroyed the ancestral Krakatau edifice, forming a 7-km-wide caldera.
Remnants of this volcano formed Verlaten and Lang Islands; subsequently Rakata, Danan and Perbuwatan volcanoes were formed, coalescing to create the pre Krakatau Island. Caldera collapse during the catastrophic eruption destroyed Danan, and Perbuwatan volcanoes, and left only a remnant of Rakata volcano. The post-collapse cone of Anak Krakatau Child of Krakatau , constructed within the caldera at a point between the former cones of Danan and Perbuwatan, has been the site of frequent eruptions since Information Contacts: Igan S.
From the end of April until the end of May, only several explosions were heard. On 26 April a weak explosion sent a white-gray ash plume m high. Between 4 and 17 May there were two blasts per week, each accompanied by a glow and white-gray ash reaching between and m high. In the week from 18 to 24 May, in addition to two explosions, a shock on the morning of 20 May registered at 2 on the MMI scale.
Anak Krakatau was very active from to , depositing 6. White-gray ash was emitted in plumes up to m above the summit. Detonations were accompanied by the ejection of incandescent material.
During many weeks of May and June thousands of explosions were recorded on seismographs. An earthquake of intensity MM II was recorded on 10 June and another of the same intensity occurred during the week ending 16 August. On several days during the reporting period the volcano could not be seen because of thick haze.
This report covers the period of 29 May June Cloud cover made visual inspection impossible on 29 May but inspection on 30 May revealed a dark gray ash plume rising m into the air. During June seismicity remained elevated. Bad weather inhibited visual observation throughout the rest of the reporting period.
Three booming explosions on 17 June coincided with a decrease in the number of volcanic earthquakes, as well as a marked increase in small explosion earthquakes. Krakatau remained at alert level 2 on a scale of 4.
Eruptive activity through late October ; infrasonic earthquakes detected. Krakatau activity continued after the previous report BGVN through October although intensity decreased relative to the 29 May eruption. The volcano's hazard status, however, did not exceed 2 on a scale of within the report period. During 27 June-2 July explosions sent ash to heights up to m, and booming sounds could be heard on three occasions. VSI reports resumed as of July when seismographs recorded 1, explosion earthquakes, compared to about a month earlier.
An infrasonic sensor detected 37 events. Satellite imagery did not detect a significant plume on this date, and no additional ash advisories were dispatched.
Activity remained similar through August. Frequent booming was heard, and high numbers of explosion and infrasonic earthquakes were detected. A volcanic ash advisory was issued on 20 August although it indicated that plumes were sparse, did not reach high altitudes, and dissipated quickly. During 22 August-4 September a white, low-density plume rose 50 m above the summit. No visual observations could be made due to heavy fog, clouds, or smog masking the summit from view during 5 September October, although seismicity indicated persistent activity.
During September, 3, explosions and 17 infrasonic events were recorded. Audible booming, however, ceased on 12 September, and activity decreased dramatically through the end of October.
Deep volcanic A-type earthquakes stopped occurring as of 10 October, although a low number of small explosion earthquakes and tectonic earthquakes continued through 30 October. No further VSI reports were issued for Krakatau in Increase in seismicity during July through August ; ash and bomb ejection. The Volcanological Survey of Indonesia VSI did not report any further activity until mid-March , when the number of shallow volcanic B-type earthquakes rose to 79 from 25 the previous week.
The number of shallow volcanic earthquakes decreased again in late March to In early April, seismic activity at Krakatau increased again. The seismographs detected 7 deep volcanic A-type earthquakes, 54 shallow volcanic earthquakes, and 7 tectonic events. Local tour operators reported a significant increase in seismic activity at Krakatau beginning during July and continuing through August. During July there were shallow volcanic earthquakes registered.
The explosion was recorded by an infrasonic microphone sensor installed at the Pasuaran post observatory. John Seach visited on 12 August and found that the volcano was not erupting then, but was steaming vigorously on the N side of the summit crater. Pulses of steam every minute reached 20 m above the summit. Lava bombs, 0. The bombs left 1. The fresh impact craters were caused by both lithic and lava bombs.
Observers on a boat 1. The top m of the active cone was steaming from multiple locations. On the NW side, 60 m below the summit, a fumarole emitted blue gas. During September the number of explosion and volcanic earthquakes increased, but the number of small explosion earthquakes sharply decreased September.
Seismic activity increases during mid-August ; Alert Level remains at 2. A thick white plume reached 25 m above the summit several times during October through December During 27 August through 16 September at Krakatau, available seismic data were dominated by explosions and shallow volcanic earthquakes table 1.
The seismograph broke on 16 September but was repaired by 26 August , when it showed a slight increase over the previous interval when data were available. No surface activity accompanied the increased seismicity. Volcanic events decreased during early September. The volcano remained at Alert Level 2 through at least 8 September. Table 1. Earthquakes registered at Krakatau during 27 August through 8 September The seismic system was down during 16 September August Courtesy of VSI. Seismicity dominated by volcanic earthquakes through at least December During 9 September through at least late December , seismicity at Krakatau was dominated by A-and B-type volcanic earthquakes table 2.
Throughout the report period, clouds obscured the view of the summit. Krakatau remained at Alert Level 2. Table 2. Earthquakes registered at Krakatau during 9 September December No data were available during September.
Courtesy VSI. Volcanic earthquakes continue; thermal alerts during July-September Seismicity at Krakatau was dominated by volcanic and tectonic earthquakes during 30 December March table 3. The hazard status remained unchanged at Alert Level 2. Table 3. Seismicity at Krakatau during 30 December March The first alert occurred on 31 July when one alert pixel was detected with an alert ratio of The anomalies increased during August and on 9 August the anomaly consisted of two alert-pixels with a maximum alert ratio of Other major anomalies occurred on 1 September four alert-pixels with maximum alert ratio of These anomalies correspond to an increase of activity at Krakatau characterized by ash and bomb emission during August and an increase in the number of explosion and volcanic earthquakes during the first half of September , reported by the Volcanological Survey of Indonesia BGVN and The coordinates of the centers of the alert pixels are tightly grouped around the summit of the main cone.
Bearing in mind that each pixel represents radiance from an area of ground more than 1 km across, the alert pixels could represent radiance from the active vent or from hot ejecta close to the vent. According to reports from the Volcanological Survey of Indonesia VSI , no visual observations were made this month due to foggy weather. The volcano remained at alert level 2 for the month. They also noted that relatively few volcanic and tectonic earthquakes were recorded during the weeks of and June Specifically, the June record consisted of 9 deep volcanic earthquakes, 19 shallow volcanic earthquakes, and 5 tectonic earthquakes; the record of June consisted of 6 deep volcanic earthquakes, 17 shallow volcanic earthquakes, and 4 tectonic earthquakes.
In the week of June, a significant increase in shallow volcanic earthquakes was observed, although no tectonic earthquakes were recorded. The sesimic record for that week showed 11 deep volcanic earthquakes and 63 shallow volcanic earthquakes. Both volcanic and tectonic earthquakes were recorded for the week of June, with 7 deep volcanic earthquakes, 61 shallow volcanic earthquakes, and 2 tectonic earthquakes detected.
Due to continued foggy weather, no visual observations could be made at Krakatau during July and through 17 August. Throughout this period the volcano remained at Alert Level 2.
Seismicity reported by the Volcanological Survey of Indonesia VSI between 30 June and 17 August consisted mostly of shallow volcanic events table 4 , although 36 deep volcanic earthquakes were recorded during the week of 30 June-6 July. Table 4. Seismicity at Krakatau, 30 June August A report of activity at Krakatau for the period August was provided by the Volcanological Survey of Indonesia. There was increase in volcanic earthquakes during this time, while tectonic earthquakes decreased.
No visual observations were made due to foggy weather. Seismicity consisted of 12 deep volcanic earthquakes, 56 shallow volcanic earthquakes, and three tectonic events. The hazard status was at Alert Level 2 on a scale of Intense activity occurred at Anak Krakatau beginning on 4 July , when gas and steam emissions increased. Based on the increased activity, the hazard status was upgraded to Alert Level II yellow on 16 July; visitors were not allowed to approach the summit or crater.
Seismicity recorded at the Kalianda station after 18 July through 15 August was variable, but did not exhibit the high numbers recorded in the first half of July. Table 5. Seismicity at Krakatau, 4 July August Minor eruptions beginning October ; seismic data for Eruptive activity in recent years was low at Krakatau.
Seismic data collected during this period figures 15 and 17 , although intermittent and variable, suggests mainly low-level activity discussed in more detail below. Starting on 23 October reports noted multiple gray plumes from eruptions lasting minutes; these vented from a crater near the summit of Anak Krakatau figure Similar eruptions were continuing in early November figure Activity during April September On 13 April increased seismicity prompted authorities to raise the Alert Level to 2 on a scale of Seismic activity decreased over the next four days to a normal level.
Visitors were banned from the summit and crater of Anak Krakatau due to toxic gas emission. Another increase in seismic activity was reported around 16 May. Elevated seismicity was also recorded on 24 September , 8 December , and June figure On figure 15, a conspicuous, longer period of high seismicity occurred during most of December , when tremor and low-frequency events also increased.
That peak on figure 15 ended prior to the end of the month. No eruptions were noted in available reports by CVGHM for these episodes of elevated seismicity in or For the intervals where data were available during the first eight months of , seismicity was generally moderate to low.
All data are acquired continuously and are transmitted to the Pasauran Observatory western Java via digital radio telemetry. In Pasauran, the data are collected and transmitted to a server in Jakarta. Three stations are located on Anak Krakatau figure A fourth station on Sertung island consists of a short-period seismometer and a digital camera with a view of Anak Krakatau.
During October , minor eruptions occurred at Anak Krakatau BGVN , an island and active vent on the rim of the famous larger caldera whose name often is misspelled as "Krakatoa. Villagers and tourists were advised not go within 3 km of the summit.
According to an Associated Press news article, "red-hot lava flares" from Anak Krakatau rose m above the S crater on 6 November. Officials said, that on that day there were eruptions coupled with 11 volcanic earthquakes, 54 shallow volcanic shocks, eight deep volcanic tremors and 44 shallower tremors.
The volcano spewed "smoke" 29 times. As reported by VolcanoDiscovery 's Tom Pfeiffer, who visited there from November, emissions were relatively constant.
He noted that all activity occurred from the newly formed crater on the upper S flank just below the old summit crater figure On 21 November, the new crater had an oval shape, approximately 50 x 70 m. Dense, dark brown, billowing ash clouds escaped in pulses from the crater at near-constant intervals of about 2 minutes, rising typically m above the crater and drifting E. A few blocks were ejected along with the ash clouds figure Pfeiffer also reported that at more irregular intervals, about min apart, more violent, small vulcanian explosions interrupted the weaker ash venting events.
The more violent explosions consisted of a sudden spray of mostly solid rocks and few incandescent scoria, followed by more powerful and turbulent ash plumes that rose up to 1 km above the crater figure Generally, these vulcanian explosions occurred after a slightly longer quiet period and, in most cases, the length of the quiet period correlated with the force of the explosion.
Pfeiffer noted that several more powerful explosions occurred at intervals of approximately hours. The strongest, on November, showered the whole island with incandescent blocks, ignited bush fires, and produced a very loud cannon-shot noise that rattled windows on the W coast of Java, 40 km away figure Other, unusually large blasts occurred at around on 21 November and at around and on 23 November figure Early on 23 November, activity became more ash-rich and the vigor of the individual events increased slightly over the next two days.
The pace of single explosions stayed at near-constant intervals of about 2 minutes. During November, ash plumes typically rose to over 1 km above the crater and were easily visible from the W coast of Java. The thermal alerts occurred on twelve occasions between 27 October and 9 December Seven of these took place between 16 and 26 November Variable eruptive activity from late to mid; plumes to 3 km altitude.
This small but growing post-caldera cone first gained attention with a eruption Simkin and Fiske, The detailed chronology of behavior during October to 3 July is sometimes sketchy, but activity was apparently quite variable. Although one or more lulls may have occurred, eruptions clearly continued into The Alert Level was lowered and raised again throughout and into as activity warranted.
People were advised not to go within 1. Activity through August According to a news article, by 22 November , seismicity had declined in frequency. Based on an Antara News article, this decline in seismic activity was interrupted by incandescent rock ejections on 20 January accompanied by plumes that rose to altitudes of 2. Seismicity again declined in early February , and eruption plumes and ejected incandescent material were not seen during 4 February to mid-April Seismicity increased during April , with the number of events per day peaking on 20 April.
Ash plumes accompanied by ejected incandescent rocks were noted during CVGHM field observations on 16, 17, and 18 April. During 22 June-1 July , the number of seismic events decreased significantly and booming noises were less frequently heard.
On July ash emissions declined, although on 1 and 2 July low level ash plumes rose to an altitude less than 3 km and drifted NW. According to an article in Antara News, eruptions increased in frequency during August On 12 August, monitoring personnel reported that active lava flows and dense emissions of "smoke" continued, but that the frequency of earthquakes and eruptions had declined.
Monitoring personnel during that period observed plumes, active lava flows, and rock ejections. Activity during March-May Seismicity increased significantly during March and remained high through 5 May.
During periods of clear weather on 25 March, white-to-gray plumes rose m above the volcano. During March and 1 April clear weather revealed ash plumes rising m. Some argue that one of the after effects of the eruption was significant cooling and increased summer rainfall that produced widespread wheat crop failure in Europe which triggered the French Revolution.
The global population today is about 10 times what it was in I'll let you do the math. While it might be possible to better protect the population in the vicinity of a volcano, it would be far tougher to deal with the potential for global impacts. Fortunately, Thomas says, "these events are very rare and infrequent. Krakatoa was only the second biggest eruption in the s in Indonesia. The eruption of Mount Tambora was so ferocious that it almost instantly killed 10, people on the island of Sumbawa and ultimately took about 90, lives.
Sign up for our Newsletter! Mobile Newsletter banner close. Mobile Newsletter chat close. Mobile Newsletter chat dots. Mobile Newsletter chat avatar. Mobile Newsletter chat subscribe. Forces of Nature. Natural Disasters. Nowhere do there seem to have been observed any shocks of a true or undulatory earthquake. Another curious circumstance was that at midday at some spots in the city no vibrations were perceived, while in the surrounding buildings they were distinctly experienced.
It was a natural conclusion, however, that an alarming volcanic eruption had taken place; but it was impossible to localize the direction of the sounds, and at the observatory there were no instruments for making such determinations.
The tremblings continued throughout the day and during the forenoon of the 21st. A thin sprinkling of ashes fell at Telok Betong and at Semangko, in Sumatra; whence the ashes came, no one could tell. At Buiteuzorg, thirty miles south of Batavia, the same phenomena were observed; while in the mountains farther to the southwest they were even more pronounced. By this time general opinion had ascribed to the west or northwest the direction whence the movements were proceeding.
Krakatoa itself was mentioned, but some of the mountains in Sumatra were considered more likely to be the seat of disturbance. On the evening of May 21st smoke was seen issuing from Krakatoa, and on the 22d it was evident that the volcanic vent was at that place. Shortly afterward the vibrations in Batavia ceased.
During the next eight or nine weeks the eruption continued with great vigor, ejecting masses of pumice and molten stone, and volumes of steam and smoke. Although the prevailing monsoon carried to the westward the greater part of the matter thrown out, a cloud of lighter particles rose higher, and, encountering an easterly current of air, some of the dust fell on the island of Timor, twelve hundred miles distant.
During these weeks vessels passed through extensive fields of pumice spread over the surface of the sea. The soundings at the spot reached two thousand fathoms. It is known that a centre of volcanic disturbance exists in the Keeling Atoll, situated six hundred miles west by south from the mouth of the strait; and it is also known that pumice ejected from the sea bottom rises to the surface. The currents of the Indian Ocean will show that any flotsam in the region between west and south of Java Head in that longitude could be drifted to the locality in which it was observed in the month of July.
In a paper read before the Royal Geographical Society, Mr. Forbes suggested that the sounds heard in Batavia on the 20th of May, which were unnoticed at places so near Krakatoa as Anjer and Merak, and which would be inexplicable if they really originated there, were the result of a submarine eruption in the Indian Ocean, somewhere southwesterly from Java Head; and that the tremors were propagated thither, perhaps, by continuous strata connecting the locale of the outburst with Batavia, Buitenzorg, and more especially with the hills to the southwest, where the manifestations were so distinctly perceived.
If such a submarine outburst did take place, Mr. Forbes suggested that somehow the orifice very soon became blocked after a great inrush of water had taken place, which, becoming transformed into steam under enormous pressure, shaped its course for the nearest old earth scar, and found vent in Krakatoa by an offshoot, probably, of the funnel of the eruption of That such large lumps of pumice should be carried westward seven hundred miles into the Indian Ocean does not seem probable, especially as the earlier outbursts were not of very unusual vigor, for no pieces of any size are reported to have fallen on the neighboring coasts of Java and Sumatra; even after those of August, no ship farther off than one hundred miles speaks of the fall of any but the finest dust and sand.
On the 21st of August the volcano increased in activity. A ship reported being unable to venture into the strait on account of the great shower of pumice and ashes. On the afternoon of the 26th there were violent explosions at Krakatoa, which were heard as far as Batavia. High waves first retreated, and then rolled upon both sides of the strait. During a night of pitchy darkness these horrors continued with increasing violence, augmented at midnight by electrical phenomena on a terrifying scale, which not only enveloped the ships in the vicinity, but embraced those at a distance of ten to twelve miles.
The lurid gleam that played on the gigantic column of smoke and ashes was seen in Batava, eighty miles away. Some of the debris fell as fine ashes in Cheribon, five hundred miles to the eastward.
On the morning of the 27th there was a still more gigantic explosion, heard in the Andaman Islands and in India, which produced along both shores of the strait an immense tidal movement, occasioning that great loss of life recounted in the daily press. The matter expelled rose to an elevation so tremendous that, on spreading itself out, it covered the whole western end of Java and the south of Sumatra for hundreds of square miles with a pall of impenetrable darkness.
Abnormal atmospheric and magnetic displays were observed, compass needles rotated violently, and the barometer rose and fell many tenths of an inch in a minute. The island is about 3 miles wide and 5.
Before the historic eruption, it had three linked volcanic peaks: Perboewatan, the northernmost and most active; Danan in the middle; and the largest, Rakata, forming the southern end of the island. Krakatau and the two nearby islands, Lang and Verlatan, are remnants of a previous large eruption that left an undersea caldera between them.
In May , the captain of the Elizabeth, a German warship, reported seeing clouds of ash above Krakatau. He estimated them to be more than 6 miles 9. For the next two months, commercial vessels and chartered sightseeing boats frequented the strait and reported thundering noises and incandescent clouds. People on nearby islands held festivals celebrating the natural fireworks that lit the night sky. Celebration would come to a tragic halt on Aug. At p. It is thought that debris from the earlier eruptive activity must have plugged the neck of the cone, allowing pressure to build in the magma chamber.
On the morning of the 27th, four tremendous explosions, heard as far away as Perth, Australia, some 2, miles 4, km distant, plunged both Perboewatan and Danan into the caldera below the sea. The initial explosion ruptured the magma chamber and allowed seawater to contact the hot lava.
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